Gluten is hidden in many common foods and used in food additives here is brief list of commonly found gluten-containing items:

FOODS TO AVOID

• Wheat
• Barley
• Oats
• Spelt
• Rye
• Triticale
• Kamut
• Malt
• Semolina
• Teff
• Far
• Farro
• Mir
• Couscous

GLUTEN CONTAINING ADDITIVES

• Cereals and cereal grains
• Caramel coloring
• Colorings
• Emulsifiers
• Flavorings
• Malt, barley malt
• Hydrolyzed plant protein (HPP)
• Hydrolyzed vegetable protein (HVP)
• Preservatives
• Starches
• Modified food starch
• Vegetable gum
• Vinegar

FOOD AND PERSONAL CARE ITEMS THAT OFTEN CONTAIN GLUTEN

• Ketchup (The vinegar in ketchup may contain gluten.)
• Canned tuna fish
• Soy Sauce
• Maple syrup (unless labeled 100% pure)
• Sauce mixes
• Corn starch (may contain anti-caking ingredient)
• Rice syrup (unless labeled gluten-free)
• Spices (flour is often added as an anti-caking ingredient)
• Medicines
• Healthcare products such as shampoo, conditioner, and soap may contain gluten.

References